On the basis of the novel heterocyclic beta-diketone, 4-sebacoylbis(1-phenyl-3-methyl-5-pyrazolone (H 2SbBP), three new lanthanide complexes Tb 2(SbBP) 3(H 2O) 2 ( 1), Gd 2(SbBP) 3(H 2O) 2 ( 2), and [Tb(SbBP) 2] [Na(DB18C6)H 2O] ( 3) have been synthesized and characterized by various spectroscopic techniques. The single-crystal X-ray diffraction analysis of 3 reveals that the complex crystallizes in the monoclinic space group C2/ c with a = 25.300(6) A, b = 19.204(7) A, c = 15.391(3) A, beta = 93.17(3) degrees , and V = 7466(4) A (3). The crystal structure of 3 is heterodinuclear and features a Tb (3+) center surrounded by two tetradentate bispyrazolone ligands in a somewhat distorted square-antiprismatic geometry. The Na (+) coordination environment is distorted hexagonal pyramidal and involves six oxygen atoms furnished by DB18C6 and one oxygen atom from a water molecule. The X-ray diffraction study of 3 also revealed an interesting 1D molecular ladder structure based on C-H/pi, intra- and intermolecular hydrogen-bonding interactions. The photophysical properties of 1 and 3 in solid state have been investigated, and the quantum yields and (5)D 4 lifetimes were found to be 4.82 +/- 0.01% and 18.13 +/- 0.82% and 1.11 +/- 0.01 and 2.82 +/- 0.02 ms, respectively.